History: Dr. Barko was the last survivor of a race of anthropomorphic
beings. He transferred the life essence of his world's greatest hero, Thunder
Bunny, into a box shaped device, which he then gave to young Bobby Caswell.
When Bobby touched the box, the essence entered into him, and now, whenever
Bobby thinks of a giant pink rabbit and claps his hands together, he transforms
into Thunder Bunny.

Comments:
Created by Martin Greim. Having initially appeared in fan publications,
Thunderbunny's first "pro" appearance was in Charlton Bullseye #6
(Charlton, 1982). A creator owned character,
Thunderbunny did not become D.C. property when
they bought many Charlton characters in the mid-1980s. Instead the character
moved to Archie Comics (under the Red
Circle Comics imprint), appearing in his own title (one issue), Blue Ribbon
#13, and Pep #393. He later had his own series published by WaRP Graphics
(and latterly Apple Comics) which lasted 12
issues, with adventures that included team-ups with various (public domain)
Golden Age heroes and the T.H.U.N.D.E.R. Agents.

Thanks to Daniel Smith for providing additional details about this character.